Semiautomatic speed changing device



Dec. 23, 1952 R. CHAMBONNEAU SEMIUTOMATIC SPEED CHANGING DEVICE 5 Sheets-Sheet l Filed May 9, 1950 m w I Dec.y 23, 1952 R. CHAMBONNEAU SEMIAUTOMATIC SPEED CHANGING DEVICE Filed May 9 5 Sheets-Sheet 2 Nw W mw www@ mm Dec. 23, 1952 R. CHAMBONNEAU 2,622,711

SEMIAUTOMATIC SPEED CHANGING DEVICE Filed May 9, 1950 5 Sheets-Sheet 5 Dec. 23, 1952 R. CHAMBONNEAU 2,622,711

SEMIAUTOMATIC SPEED CHANGING DEVICE Filed May 9, 1950 5 Sheets-Sheet 4 7E /l @Ewa a A k A Dec. 23, 1952 R. CHAMBONNEAU SEMIAUTOMATIC SPEED CHANGING DEVICE 5 Sheets-Sheet 5 Filed May 9, 1950 m6, S s s Z7.. f N

, NQ xa Q\ mm. Nm. Nm. wm. No.

Patented Dec. 23, 1952 UNITED STATES PATENT QFFICE Application May 9, 1950, Serial No. 160,920

/ In France October 28, 1949 13 Claims.

When changing speed in a motor vehicle, it is necessary, as known, to perform a plurality of combined operations, viz. to lower the clutch pedal after releasing the accelerator, to actuate the gear shift lever in order to bring it to the position corresponding to the desired velocity, to release the clutch pedal while stepping on the accelerator.

In motor vehicles provided with an automatic speed changing device, these combined operations are reduced to a mere actuation of a lever or a pedal; however, automatic speed changing devices are very costly, often delicate, and further hinder somewhat the freedom of the driver in controlling the engine.

The present invention has for its object a semiautomatic speed changing device designed so that the actuation of the gear shift lever automatically causes declutching of the engine, coupling and opening of the butterfly throttle taking place simultaneously and progressively, after said lever has been brought to the desired position and released, either automatically or by actuating the accelerator pedal. Both operations, i. e. coupling and acceleration, being synchronized, a perfect pick up of the engine for the new selected velocity, is ensured.

According to a form of the present invention, the control of the clutch mechanism and of the buttery throttle are ensured by vacuumoperated members; for this purpose, these members are connected to the suction manifold of the engine through a slide-valve whose opening and whose locking in that position, are controlled by an electric circuit which is automatically closed at each actuation of the gear shift lever, the unlocking of the slide-valve taking place after closing a second circuit by means of a switch controlled by the accelerator pedal.

The invention also concerns the various members enabling to ensure the above operations, viz. the slide-valve, the switch controlled by the gear shift lever and the switch controlled by the accelerator pedal.

In a further embodiment of the invention, the locking of the slide-valve being done without, coupling and opening of the butterfly throttle automatically and progressively take place as soon as the driver releases the gear shift lever after having brought it to the position corresponding to the new desired speed.

According to another form of the invention, the closing of the slide-valve control electric circuit is effected by a switch actuated by the brakepedal, a second switch being provided for breaking at will the circuit, thus rendering it independent from the action of the brake-pedal. Moreover, the invention includes a modication to this control device through the brake-pedal so as to allow on the one hand braking at high speeds without affecting the clutch and to ensure on the other hand automatic declutching of the engine at low speeds by stepping on the brake-pedal.

Other objects and advantages of the invention will be apparent during the course of the following description.

ln the accompanying drawing forming a part of this application and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a general view of the device fitted up on a motor vehicle engine,

Fig. 2 is a section of the gear Shift lever knob showing the control switch,

Figs. 3 and 4 show, in two different positions, the clutch control member,

Figs. 5 and 6 show, in two different positions, the dilerential relay device controlling the carburetor,

Fig. 7 is a general View of a further form of the present invention,

Figs. 8 to 17 are detail views of Fig. 7,

Figs. 8 and 9 are longitudinal sections of the clutch control member, in two diiierent positions,

Fig l0 is a Vertical section of the throttle control device,

Fig. ll is a perspective view of a switch actuated bythe piston of the clutch control cylinder,

Fig. l2 is a plan-view of this switch,

Fig. 13 is a section taken along line XIII-XIII of Fig. 12,

Figs. 14, l5 andfl are diagrams illustrating the operation of the switch shown in Figs. 1l to 13,(

and

Fig. 17 is a longitudinal section of a vacuumoperated switch.

The device of the invention is fitted up on a motor vehicle as shown in the drawing.

The gear shift lever l (Fig. l) arranged as shown under the steering wheel 2, is completed by a pear-shaped knob 3 which constitutes as described hereafter, a switch for controlling the feed-circuit of a coil 4 (see also Fig. 3) belonging to an electromagnetic valve 5 which includes a second coil 6 whose feed-circuit is controlled by a switch 'l operated by a relay 8. The latter is hinged, on the one hand through an upper extension 9, on the lever I6 of the butterfly throttle ll of a conventional carburetor I2, and on the other hand through a lower extension 8a, on a bent lever i3 pivoting about i4 and connected further, through an appropriate linkage i5, to the accelerator pedal i5.

The electromagnetic valve 5 connected, through a pipe il, to the suction manifold la of the engine; it is further connected, through a pipe I8, to a cylinder |53 containing a piston |Sa. This piston lea is connected on the one hand. through a linkage 25. to the clutch pedal 2| pivoting about` 22, and on the other hand, through a joint 23, to the moving part of a conventional clutch (not shown on the igure).

A flexible pipe 24 connects pipe |8.to .a.differential relay 8. The conventional battery 25 'feeds the control circuits of coils 4 and '5 of 'the 'electromagnetic valve.

Referring to Fig. 2, the control switch of coil 4' is constituted by a particular arrangement vof the end portion of the gear shift lever which ends as usual in a pear-shaped knob facilitating handlingby the driver.'

According to the invention' thisend portion is essentially composed of two parts 5 and made of* insulating material, part 25 being fast with lever l', for instance by screwing it thereon. This part 25 extends through a cylindrical portion at the extremity of which ametal ring 25 connected to a'conductor 25 leading to coil 4- (see also Fig. l), is' secured. This cylindrical portion 2'! ha'sa boring 21a inside which a spring is located. The latter is fast with a small plug electrically connected (through spring to conductor SZfleading 'to `the battery 25.

The plug 3| urged by spring 3S, is permanently applied on a cup-shaped contact member 53 embedded in a head 34' screwed on the part 5 which, owing to this fact, tends to moveaway from the xedpart 25,' a spacer-sleeve 35 inserted between the edge 35 of the knob 'Li-3ft and the ring 22, limits'the displacement of 'this knob.

The feed-circuit of coil 4-is closed, i. e. conductors 29' and 32 are connected, merely by pushe ingthe movingknob 3-34 so that, by compressing spring 35, the bottom of the cup-shaped member 33-comes into contact' with the ring 28. .f

In order not to be restricted, for closing the circuit to exerting a push inY a direction parallel to the'axis of lever i, the moving knob is tted up with sufficient' clearance on the cylindrical por-- tion2l`s'o' as'toallow pushing obliquely this knob 3-34, thus causing the rim of the cup-shaped member'ito come into contact with ring 28.

Under these circumstances, every time the driver actuat'es lever by handling it through its knob, he willl automatically close the feedcircuit of coil 4, this circuit being automatically broken as soon as he releases lever i;

The electromagnetic valve 5 (Figs. 3 and e) is constituted by a main body-portion at one end of which a casing 31 is fitted up; this casing contains coil 4 which is therefore arranged coaxially with respect tothe body-portion of the valve. The latter comprises an axial boring inside which a slide-valve 39 can move. In the position shown in Fig. 3 (which is the position at rest); slide-valve 39 is applied at one end on a seat 4Q' at the extremity of boring til, thus cutting offpipe connected through a duct 4| to boring 38, from pipe I8 connected to said boring through a duct 42.

Slide-valve 39 is pierced along its axis with a duct 43 opening up in a diametre-l duct 44 both ends of which are connected through an annular groove 45. In the vicinity of groove 45, the slidevalve comprises a circular slot 45 into which the 4f tip of a plunger 41 can penetrate; this plunger is controlled by the coil 6 as described hereafter.

The body-portion of the valve comprises a duct 4S which connects boring 38 to the atmosphere. A valve-screw 49 enables to adjust the passage cross-section of duct 48.

The plunger 41 comprises a portion 5S of sulciently large diameter for fitting up therein a compression spring 5| inserted'between the bottom of the box 5|). and ak mildf'ironl member 52 carried by a casing 53 secured to the body-portion ofthe valve and enclosing the coil 5.

Coil G isconnected through a conductor 54 (seeFig: l) tofone of 'the terminals of a switch 'tof a diierential relay il, the other terminal of this switch being connected through a conductor 55to'the battery 25.

Therelay'S is constituted by a cylinder containing a piston 56 (Figs 5 and 6) whose rod 5'! is provided with a thrust bearing 5B supporting a small cup-shapedmember 5S. A further cupshaped member i'can slide along rod 5'|'and is urged away from member 5S by a spring 6| applying said member 6G on the tip of a spring 52.supportedon the cylinder of the relay.

The cup-shaped members 59 and 66 are connected to conductors 55 and 54 respectively and they form the two contacts of the above-mem tioned switch The rod15l extends beyond the thrust bearing 58 and Yis linked through itstip Sto the throttle lever |5.-

Towards its lower end, the cylinder of the relay comprises a duct'ifconnected to the flex,- ible pipe 24. A spring 54' urges piston 5.5,away from this end.

'Ihe above-described device operates as follows:V

When the, driver wants to change gear, he grips the knob 3-34 for the purposeA of actuating lever By doingv this, he exerts automatically a push on this knob andhence closes the feedcircuit'oficoil'i, through conductors 32 and 29.

This coillwhen energized causes the slide-valve 59 tomove from the position shown in Fig. Sto that' shown in Fig. 4'. In its motion of Atranslation, rod 3S' abuts onto a mild iron platelet Sla.y secured to the casing 37, and it opensI ducts 4| and 42 which are hence connectedv together through boring 58.

Slide-valve 39 is held in its new position (Fig. 4) even when the driver has released the gear shift lever owing to the engagement of thev tip of plunger 4'? urged by spring 5| into the circular groove 45.

The underpressure prevailing in the suction manifold la (Fig. l) ofthe engine, is transmitted through pipe i8 to cylinder I9; piston |9a therefore moves towards the left. This translation motion conveyed to the moving member of the frictionclutch, automatically causes declutching of the driving wheels.

At the same time, the underpressure prevailing in pipes i8 and 24 is conveyed to piston 5,5 (Figs.

' 5 and 6) piston 55 is urged by this underpressure towards the bottom of the cylinder, i. e. the` relay tends to contact; but owing to the effort conveyed by spring 64 toV cylinder 8 and to linkage |5, the accelerate pedal l5 moves upwards. The butterfly throttle being in the Closing position, it remains tightly held in that position and prevents further displacement of piston 56.

The throttle Will remain closed until the driver, by exerting sufficient pressure on pedal I6, will' have brought about a certain displacement thereof; this motion conveyed through linkage Iii-I3 to cylinder 8, displaces upwards the latter against the action of spring 64. Because of this relative displacement of the cylinder and of the piston, spring 62 is compressed and its action becomes prevailing over that of spring 6I which gets suinciently compressed for allowing contact between the cup-shaped members 59 and 69 (Fig. 6). This contact causes the switching on of coil 6 (through conductors 54 and 55, Fig. l). This coil being energized, it attracts plunger 41 forming its armature; the latter moves then from the position shown in Fig. 4 to that shown in. Fig. 3.

Slide-valve 39 being no longer locked by plunger 41 nor urged by coil 4 which is de-eneru gized, returns (owing to the underpressure prevailing in pipes Il', I8 and in boring 3S) to the `position shown in Fig. 3 and hence connects pipe I8 to the atmosphere through duct 49 while obturating duct 4I. The rise in pressure up to atmospheric pressure lasts a time determined by the position of the screw 49.

Piston Ilia being no longer subjected to suction, returns to its position of rest, owing to the action of the clutch-spring; the clutch is therefore urged back to its operative position for which the wheels are driven by the engine.

At the same time, the cylinder of the differential relay is connected to the atmosphere. The piston 59 being no longer subjected to suction moves upwards owing to the action of spring 64. This translation motion of the piston and of its rod causes rst the lever I0 to move angularly so as to open the throttle I i oi the carburetor, and then-when the stroke of the piston will havebeen suiicient for the tension of spring t2 to become less than that of spring EiI-the cupshaped members 59 and 59 to move apart and hence to switch oi' coil t, plunger 41 remaining however in its position of rest shown in Fig. 3, owing to the displacement of slide-valve 39 towards the right.

It is hence clear that as soon as the driver actuates the gear shift lever, he automatically causes the declutching of the driving wheels and the closing of the butterfly throttle; this declutching and this closing of the butterfly throttle take place until the driver, by stepping on the accelerator, actuates an unlocking device arranged in such a way that, after a certain time which may be adjusted (by the screw a9 controlling the passage cross-section of they atmosphere duct 48), coupling be automatically reestablished while the progressive opening of the butterfly throttle takes place.

According to another form ci the invention (Figs. '1, 8 and 9) the locking device of the slidevalve 39 is done without, so that, as soon as the feed-circuit of coil i is broken, the slide-valve 39 which lies in the position shown in Fig. 9, returns, owing to the underpressure prevailing in ducts 4I, 42, to the position shown in Fig. 8 whereby duct di is obturated, while duct 42 and hence pipe I8 are connected to the atmosphere through the adjustable port 48.

Under these conditions, it is clear that, on the one hand, the actuation of lever I in order to bring it to the position corresponding to the new selected velocity, automatically causes cylinder I9 yto be connected to the suction manifold Ia of the engine, thus bringing about the displacement of piston I9a and hence declutching the engine, and that, on the other hand, the release of lever I in its new position automatically cuts off cylinder I9 from the suction manifold Ia, cylinder I9 being further connected to the atmosphere, whereby after a certain time adjusted by obturating mo-re or less duct 48 by means of screw 49, the piston is brought back to its original position for which the engine is coupled.

This arrangement avoids having to step on the accelerator in order to unlock slide-valve 39 as described above.

In order to ensure a proper pick up of the engine, it is necessary, when coupling, to open progressively the buttery throttle, both when the vehicle is at rest and the driver goes through first gear, and when the vehicle is running and the driverrgears up, for in the latter case, when actuating lever I, the driver releases, from habit, the accelerator.

According to the present embodiment of the invention, the control linkage of throttle II which comprises as usual a lever ID, a rod I5a, a bent lever I3 and a spindle I5 linked to the pedal I6, is completed by a small flange 1I) (Figs. 7 and l0) secured to rod Ia, for instance, by means of a sleeve I5b.

The flange 19 is pierced with a hole through which a rod 1I can freely slide; this rod 1I is threaded at its lower part and provided with a nut and a check-nut as shown in 12, this nut constituting a stop adjustable along rod 1I for abuting against ange 1I).

At its top, rod 1I ends in a spherical cap 13 engaged in a corresponding socket provided at the foot of an armature 14 urged by a coil 15 located inside a casing 15a secured to the engine.

When the feed-circuit of coil 15 is closed, the armature 14 is attracted and, through rod 1I, it drags upwards the rod I5a, thus causing the butterfly throttle II to open.

The flange 19 is only dragged along by rod 1I when the latter moves upwards so that it is possible to actuate the butteriiy throttle I I in the usual way, by means of pedal I6.

The feed-circuit of coil 15 is controlled by a switch which only closes the circuit when piston I9a moves back to its position of rest for which the engine is coupled, whereas in its leftward stroke which brings about declutching, the piston does not act on said switch.

Owing to this fact, during progressive coupling of the engine, the butterfly throttle II is also progressively opened.

Referring to Figs. 1l to i6, the switch controlling the circuit of coil 15 is seen to comprise a xed support secured for instance to cylinder I9 (Fig. 7); on this support is tted an insulating platelet "Iii having two small iianges 11 supporting a small axle 18 about which a T-shaped member can pivot; the branch 19 of this member comprises a stud connected to a wire 8l leading to coil 15 (Figs. '1 and 1l). This stud 80 is arranged opposite a strip 32 with which it cornes into Contact when the branch 19 is angularly displaced about its axle 19. This strip 82 is connected to a conductor 83 leading to the battery 25. A spring 84a inserted between the branch 1% and the platelet 16 normally holds branch 19 in the position for which there is no contact between the stud 89 and the strip t2,

The branch 19 is completed by a branch 84 which constitutes a kind oi cam along which a roller 85 can roll; the latter is carried by a lever 86 pivotally mounted at 81 on a support 88 secured to the spindle Ib of the clutch control Y piston.

7.. tion shown in Figs.. ll, 14`and 16; this position is 'determined bythe abutment of the lower rim 9i! of lever 'BQ on thebaseplate 9| of the support 83; Lever 85 cantherefore only pivot about axle SEI inopposition to the action of spring 89.

Referring to Figs. 7 and le, it is noted that when, piston lilal is in the position of rest (engine coupled) lever 86 lies at the right of cam 84.

When, owing to suction, piston |9a moves towards lthe left inV cylinder l .(for declutching the engine), the roller 35 driven in the direction of arrow f will meet the cam 34 and the lever 86 will pivot in opposition to the action of spring S5, so as tov `come in the position shown in Fig. camxtfi held in placeby the action of spring a will remain in its original position for which stud 88 is at a distance from strip 82; consequently, the feed-circuit 83-8| of coil 'l5 will remain open and hence, rod |5a not being driven, the' butterfiy throttlewill be held vclosed owing to the action of `its return spring.

On the contrary, when piston ld returns to its position of rest, the roller 85 (which, during the stroke of piston lea bringing about declutching, hasmoved rbeyond cam 84,V as shown in Fig. 1l) moves inl the direction opposite to that of arrow]e and will meet cam 24, but lever 86 which rests on thelbase-plate Si, is held in the vertical position (Fig. 16,). Hence, cam 34 is raised in opposition to the action of spring Sea, and the stud 8D comes into contact with the strip 82, thus closing the feed-circuit 83-{31 of coil 'i5 and causing the Ithrottle to open.

According to another form of the invention, the switching on of coil 4 may be effected by lowering the Vbrains-pedal. It is enough for this purpose to connect conductors 29v and 32 through conductors 65 and 66 (shown in dotted lines in Figs. l and 7), to a switch 61 controlled by the said brake-pedal; this switch 67 may merely be the braking signal switch. In other words, the former switch located in, the knob of the gear shift'lev'er is short-circuited when this switch 61 is Closed..

Under thesev conditions every time the driver steps on the brake-pedal, coil i is energized, switch El. playing the part formerly played by switch 28-33. A further switch 63 located for instance on the instrument panel, enables to put in circuit, atr will, this device whose use is particularly convenient for town trainc, for it is necessary to stop and startV alternately and often.

In the embodiment of Fig. 7, a device is provided for enabling the driver to put on the brakes .at high'fand medium speeds without thereby acting on the clutch.

Fpr this purpose, the energizing circuit of coil comprises, besides switches 61 and 68, a switch 652, shown inFig. 17 and arranged so as to allow switching on coil 4 when the engine runs slowly and, on the contrary, to prevent switching on whenthe engine runs at a high rate and the driver putseon the brakes.

Switch 59 which is connected to the feed-circuit of coil. el through studs 532 comprises a plate 93. provided with two studs et which are normally heldin contact with the studs 92 owing to the action of a spring 95 inserted around a rod 96 carrying the plate t3. This rod 9@ leads to a cavity dl and is secured to a diaphragm 98 constituting a partition dividing cavity 97.

This cavity 9.1 is connected to a duct 99 which is normally obturated by a ball or valve l Gil urged by a spring |0| whose tension can be adjusted by means of a screw |02.

The spring |0| is located in an enclosure connectedthrough a duct |03 and a pipe |04, to the suction manifold la of the engine (Fig. 7).

The spring |0| is given such a tension that its action on ball be prevailing over that produced by suction exerted on said ball, when the engine runs slowly, so that, under these conditions, ball |00 remains applied on its seat and obturates duct S9; but as soon as suction reaches a predetermined value (which is related to the rate of the engine after the driver has released the accelerator in order to step on the brakepedal), its action becomes prevailing over that of spring IGI and the ball |00 is driven away from its seat, thus opening duct $9. The diaphragm 98 is then subjected to suction and is deflected, thus dragging, in opposition to the action of spring 95, the rod 96 and the plate 93.v The studs 94 are moved away from the studs 92 and coil lll cannotl be switched on by switch S'l when the brake-pedalv is lowered.

Hence, when the vehicle is at rest and the engine is slow running or when the vehicle is moving at a low velocity, the driver by stepping on the brake-pedal, actuates switch 61 thus switching on coil i (obviously the hand switch 68 on the instrument panel, is supposed to be closed) coil i being energized, it causes, as described above, declutching. By releasing the brake-pedal, the driver automatically causes switch 61 to open thus switching off coil 4.

On the other hand, when the vehicle runs at a relatively high velocity, the action of the driver on the brake-pedal (the butterily throttle being then closed), has no effect on the clutch owing to the fact that suction keeps plate 93 away from the studs 92.

If the driver keeps stepping on the brake-pedal, he will automatically cause declutching when the vehicle having suilciently slowed down, it will no longer drive the engine, thus reducing suction to a value which is insufcient for balancing the action of spring 0|.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims. In particular, the suction control members instead of being directly connected to the suction manifold of the engine, may obviously be connected to an auxiliary tank fed by the engine 01, in the case of engines of low cylinder-capacity, to a pump driven by the engine.

What I claim is:

1. A semi-automatic speed changing device for a vehicle provided with wheels connected to an engine through a clutch and a gear-box controlled by a gear shift lever, said engine being fed through a carburetor provided with a butteriiy throttle connected through a linkage to an accelerator pedal, said device comprising pressureoperated means for actuating said clutch; piping means between said pressure-operated means and a source of pressure adapted to feed the same; electromagnetic valve means for controlling said piping means; a source of electric current adapted to energize said valve means and connected thereto through an electric circuit; in said circuit a switch adapted to be operated while the gear shift lever is actuated and to be returned to its initial position when said gear shift lever is released; electromagnetically operated means for progressively openingsaid butterily throttle; a source `of g electric current adapted to energize said electromagnetically operated means and connected thereto through electric conductors; a switch in at least one of said conductors; and means for momentarily actuating said latter switch when said pressure-operated means bring about coupling of said clutch, whereby said electromagnetically operated means momentarily cause said butterfly throttle to open.

2. A speed changing device according to claim 1 wherein the electromagnetically operated means comprise a rod; connecting means between said rod and said linkage for displacing the latter in the opening direction of said butteriiy throttle; and a coil adapted to control said rod.

3. A speed changing device according to claim 1 wherein the pressure-operated means is a vacuum-operated cylinder containing a piston linked to the clutch and adapted to bring about declutching when subjected to suction; and wherein the means for momentarily actuating the latter switch comprises a pivoting arm carried by a rod integral with said piston; means for preventing said arm from pivoting beyond a predetermined position; a return spring adapted to urge said arm in said position; a cam arranged on the path of the tip of said arm, so that said arm comes into contact with and moves past said cam when said piston effects a complete stroke; a pivoting lever integral with said cam; a return spring adapted to act on said lever for urging said cam towards said arm, the relative tensions of said return spring being such that, and said position being predetermined so that, when the piston is actuated for declutching the engine, said arm is caused to pivot after coming into contact with said cam, whereas when the piston moves for coupling the engine, said arm remains in the predetermined position thus causing said lever to pivot during contact between said arm and said cam.

4. A semi-automatic speed changing device for a vehicle provided with wheels connected to an engine through a clutch and a gear-box controlled by a gear shift lever, said engine being fed through a carburetor provided with a butterfly throttle connected through a linkage to an ac celerator pedal, said device comprising pressureoperated means for actuating said clutch and pressure-operated means for actuating said butterfly throttle; piping means between said pressure-operated means and a source of pressure adapted to feed the same; electromagnetic valve means for controlling said piping means; electro- Y magnetic locking means associated with said valve means; a source of electric current adapted to energize said electromagnetic means through respective energizing circuits; in the energizing circuit of said valve means, a switch adapted to be operated while the gear shift lever is actuated and to be returned to its initial position when said gear shift lever is released; and in the energizing circuit of said locking means, a switch adapted 'to be operated when the accelerator pedal is lowered.

5. A speed changing device according to claim 4 wherein the electromagnetic valve means cornprises a substantially axial boring; a duct branching orf from said boring; a conduit branching ofi from said boring in the vicinity of said duct; a passage connecting said boring to the atmosphere; means for adjusting the cross-section of said passage; a slide-valve adapted to slide along said boring and to control said duct, said conduit and said passage so that, in one position of said eil.)

slide-valve, said duct and said conduit are cut oir from one another and said conduit and said passage are connected up to one another, and in another position of said slide-valve, said duct and said conduit are connected up to one another and said passage is cut orf; and a coil adapted to control said slide-valve; wherein the piping means comprises piping connecting the pressureoperated means to said conduit; and further piping connecting the source of pressure to said duct; and wherein the electromagnetic locking means comprises a plunger adapted to engage a notch in said slide-valve when the latter is in the position in which the duct and the conduit are connected up to one another; a spring adapted to urge said plunger into engagement with said notch; and a coil adapted to control said plunger, whereby the latter is disengaged when the coil is energized.

6. A speed changing device according to claim 4 wherein the pressure-operated means for actuating the butterfly throttle comprises a cylinder fast with the linkage to the accelerator pedal, said cylnder being connected to said piping means down-stream with respect to said valve means; a piston adapted to move inside said cylinder; a rod integral with said piston and hinged to said buttery throttle; a spring inside said cylinder adapted to urge said piston in opposition to the action of pressure; a second spring outside said cylinder, supported thereon and arranged around said rod; a contact member at the end of said second spring and adapted to slide along said rod; a further contact member carried by said rod; and a third spring between said contact members and adapted to urge them away from one another; and wherein the switch located in the energizing circuit of the locking means is constituted by said contact members.

' 7. A semi-automatic speed changing device for a vehicle provided with wheels connected to an engine through a clutch and a gear-box controlled by a gear shift lever, said wheels being provided with brakes controlled by a brake-pedal, said device comprising pressure-operated means for actuating said clutch; piping means between said pressure-operated means and a source of pressure adapted to feed the same; electromagnetic valve means for controlling said piping means; a source of electric current adapted to energize said valve means and connected thereto through an electric current; in said circuit a switch adapted to be operated while the gear shift lever is actuated and to be returned to its initial position when said gear shift lever is released; and a second switch arranged in parallel with the former one and adapted to be actuated when the brake-pedal is lowered and -to be returned to its initial position when said brakepedal is released.

8. A semi-automatic speed changing device for a vehicle provided with wheels connected to an engine through a clutch and a gear-box controlled by a gear shift lever, said wheels being provided with brakes controlled by a brakepedal, said pedal controlling a braking signal switch, said device comprising pressure-operated means for actuating said clutch; piping fmeans between said pressure-operated means and a source of pressure adapted to feed the same; electromagnetic valve means for controlling said piping means; a source of electric current adapted to energize said valve means and connected thereto through an electric circuit; in said circuit a switch adapted to be operated 1 1 While the gear shift lever is actuated and to be returned to its initial position when said gear shift lever is released, said switch being arranged in parallel with said braking signal switch.

9. A speed changing device according to claim 7 wherein a hand-operated switch is arranged in series with said second switch.

10. A semi-automatic speed changing device for a vehicle provided with wheels connected to an engine through a clutch and a gear-box controlled by a gear shift lever, said wheels being provided with brakes controlled by a brake-pedal, said device comprising pressure-operated means for actuating said clutch; piping means between said pressure-operated means and a source of pressure adapted to feed the same; electromagnetic valve means for controlling said piping means; a source of electric current adapted to energize said valve means and connected thereto through an electric circuit; in said circuit a switch adapted to be operated while the gear shift lever is actuated and to be returned to its initial position when said gear shift lever is released; a second switch arranged in parallel with the former one and adapted to be actuated when the brakepedal is lowered and to be returned to its initial position when said brake-pedal is released; a third switch arranged in series with said second switch; and speed responsive means for actuating said third switch, whereby said third switch is closed when the vehicle is at rest and when it runs at a speed lower than a predetermined value, and it opens when the vehicle runs at a speed higher than said value.

11. A speed changing device according to claim 10 wherein the engine is fed through a suction manifold; wherein the speed responsive means comprise an enclosure; a connection between said enclosure and said suction manifold; a valve adapted to control said connection; a spring adapted to urge said valve in closing position with respect to said connection; means for adjusting the tension of said spring; a diaphragm across said enclosure adapted to divide the latter into two chambers; a rod secured to said diaphragm; contact members fast with said rod; conducting studs opposite said contact members; and a spring adapted to urge said members into contact with said studs; and wherein the third switch is constituted by said contact members and said studs.

12. A semi-automatic speed changing device for a vehicle provided with wheels connected to an engine through a clutch and a gear-boxv controlled by a gear shift lever, said engine being fed through a carburetor provided with a butteriiy throttle connected through a linkage to an accelerator pedal, said device comprising pressure-operated means for actuating said clutch; piping means between said pressure-operated means and a source of pressure adapted to feed the same; electromagnetic valve means for controlling said piping means; a source of electric current adapted to energize said valve means and connected thereto through an electric circuit; in said circuit a switch adapted to be operated while the gear shift lever is actuated and to be returned to its initial position when said gear shift lever is released; and means under control of said electromagnetic valve means for progressively opening said butterfly throttle when said electromagnetic valve means is released.

13. A speed changing device according to claim 12 wherein the gear shift lever is provided with a knob consisting of a xed part secured to said lever and provided with an axial projection and a movable part provided with a central recess wherein said axial projection is introduced, said movable part being urged away from said xed part by a spring, the displacement of said movable part away from said fixed part being limited by a stop arranged on said projection of said xed part; and wherein the switch consists of two conducting members arranged opposite one another, one of said members being externally carried by said axial projection of said fixed part and the other of said members being secured to said movable part within said recess and being adapted to come into contact with the former member and to be distant therefrom according to the position of said movable part relatively to said xed part.

ROGER CHAMBONNEAU.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

